title: Dicer is down-regulated in clear cell renal cell carcinoma and in vitro Dicer knockdown enhances malignant phenotype transformation.
abstract: OBJECTIVE
  Although emerging evidence has shown that the deregulation of micro-ribonucleic acid (RNA) biogenesis machinery is involved in various human malignancies, this role has not been investigated in clear cell renal cell carcinoma (ccRCC). This study aims to determine whether Dicer, a key enzyme responsible for biogenesis of microRNA, is deregulated in ccRCC. The biological roles of Dicer in vitro are also determined.
  
  
  METHODS
  The expression of Dicer at messenger RNA and protein levels was detected by real-time quantitative polymerase chain reaction and western blot, respectively, in human kidney tubule epithelial cell line, nonmetastatic 786-O ccRCC cell line, and metastatic ACHN ccRCC cell line, as well as in 42 cases of ccRCC surgical specimens including 14 cases with distant metastasis and their corresponding adjacent normal renal tissues. Dicer expression levels in specimens were also measured by immunohistochemical staining. Knockdown of Dicer expression in 786-O and ACHN ccRCC cell lines was achieved by transfecting short interfering RNA against Dicer. The effects of Dicer on cell proliferation, migration, and invasion were detected by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, flow cytometric analyses, and Boyden chamber Transwell assay, respectively.
  
  
  RESULTS
  Compared with human kidney tubule epithelial cell line, Dicer expression levels were significantly down-regulated in 786-O and ACHN ccRCC cell lines, with the metastatic ACHN ccRCC cell line having even lower levels. Meanwhile, Dicer expression levels were significantly down-regulated in ccRCC surgical specimens compared with adjacent normal renal tissues, with the metastatic ones further reduced, and Dicer messenger RNA levels were significantly correlated with overall tumor-node-metastasis stage of ccRCC. In vitro, the knockdown of Dicer significantly promoted cell proliferation, migration, and invasion.
  
  
  CONCLUSIONS
  Reduced expression of Dicer may play a role in the tumorigenesis of ccRCC and further decline may be associated with distant metastasis of ccRCC.
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ai
authors.affiliation: Medical School, Nankai University, Tianjin, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Weihao
authors.initials: W
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Erlin
authors.initials: E
authors.lastname: Song
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Baojun
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Taoping
authors.initials: T
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Kidney Diseases, Department of Urology, Military Postgraduate Medical College, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China. Electronic address: xzhang@foxmail.com.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D053487:DEAD-box RNA Helicases / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D010641:Phenotype; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D043244:Ribonuclease III / Q000235:genetics* / Q000378:metabolism
chemical_list: C408087:DICER1 protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases
keywords: Clear cell renal cell carcinoma; Dicer; Invasion; Metastasis; Migration; Proliferation